This invention relates to weighing scales, and more particularly to adjustment mechanisms for the mountings of the flexures of such scales.
Weighing scales with parallel, V-shaped or triangular flexures are well known, as shown, for example, in Lee U.S. Pat. No. 4,383,586. Exact parallelism of the flexures in such scales is extremely important for satisfactory operation of the scale. Scales of this type therefore typically have some kind of mechanism for adjusting the location of one or more of the flexure mountings to ensure parallelism of the flexures. For example, in the Lee patent, upper flexure mountings 136b and 136c are respectively mounted on elongated members 124 and 126 which can be pivoted by screws 130 and 131 to adjust the vertical locations of mountings 136b and 136c. While the Lee structure is said to have the advantage of permitting "vernier control" of the locations of the flexure mountings, the Lee structure is also fairly large and bulky.
A more common type of flexure mounting adjustment is shown in Knothe et al. U.S. Pat. No. 4,153,126. In Knothe FIGS. 3 and 4 upper flexure mountings 9a are adjustable by rotation of adjusting screws 10. It is extremely difficult to achieve fine adjustments with a structure of this type. Adjusting screws of very small pitch are relatively expensive, and even with such screws, only a relatively coarse adjustment is possible.
In view of the foregoing, it is an object of this invention to improve the adjustment mechanisms for the flexure mountings in weighing scales.
It is a more particular object of this invention to provide relatively small flexure mounting adjustment mechanisms which allow extremely fine adjustments over a wide range without the use of excessively costly components.